Lennox 59K21 Control Board Refrigerant This is an SPST (Single

This is an SPST (Single Pole Single Throw) switch with a Normally Open (NO) contact function that closes on rising pressure

If you observe constant dripping or a steady discharge from the relief valve port despite the checks being clean

What are the electrical ratings for the contacts on this control

When diagnosing a furnace pressure switch error or a failed draft inducer motor

The housing is constructed from rugged plated steel

Lennox 59K21 Control Board Refrigerant This is an SPST (SingleThe Lennox 59K21 Control Board is a fundamental integrated ignition control module designed for high performance residential gas furnaces. As a high reliability "brain" for your heating system, this board manages the critical sequence of operations, including the furnace ignition control, inducer motor timing, and blower transitions. Technical data confirms that the 59K21 is identical to 59K2101, providing a direct OEM HVAC replacement part for